IC Imaging Control ActiveX

ICImagingControl.OverlayUpdate Event

ICImagingControl.OverlayUpdate Event

This event is called after a new frame has been delivered by the video capture device.
Syntax:
Private Sub OverlayUpdate(ByVal Overlay As ICImagingControlCtl.OverlayBitmap, _
                               ByVal SampleStartTime As Double, _
                             ByVal SampleEndTime As Double )
Parameter Description
Overlay

Specifies the Imaging Controls OverlayBitmap object

SampleStartTime

Specifies the sample start time in seconds. See remarks section for more information.

SampleEndTime

Specifies the sample end time in seconds. See remarks section for more information.

Remarks:

The OverlayUpdate event is called after a new frame is available. In the OverlayUpdate event sub, text or graphical elements can be drawn in the new frame. Therefore, it is possible to insert individual information on each individual frame.

The sample time is the time that has been passed, since ICImagingControl.LiveStart has been called. The time resolution is seconds. The duration between SampleStartTime and SampleEndTime is equal to the current frame rate.

This event is called before the ICImagingControl.ImageAvailable event occurs.

Exceptions that occur in the OverlayUpdate event will get lost in the system. Therefore, bugs in the code that cause an exception cannot be recognized. To avoid this, use an On Error Goto ... construct. The On Error Goto ... statement should be put at the beginning of the event handler. If you need to display error messages, do not use a message box. Use a "debug trace" instead (e.g. Debug.Print ... ). This is very important, because otherwise the system may run into a deadlock which will cause the application to hang.

Sample:

This example demonstrates how to write a frame counter on the live video. FrameCount is a global declared variable in the form.

Private Sub ICImagingControl1_OverlayUpdate(ByVal Overlay As ICImagingControlCtl.OverlayBitmap,  _
                                            ByVal SampleStartTime As Double, _
                                            ByVal SampleEndTime As Double)
    FrameCount = FrameCount + 1
    Overlay.DrawText RGB(255, 255, 0), 0, FrameCount
End Sub
See also: ICImagingControl, OverlayBitmap, ICImagingControl.LiveStart, ICImagingControl.ReferenceTimeStart, ICImagingControl.ReferenceTimeCurrent

<< ICImagingControl

Get in touch with us


About The Imaging Source

Established in 1990, The Imaging Source is one of the leading manufacturers of industrial cameras, frame grabbers and video converters for production automation, quality assurance, logistics, medicine, science and security.

Our comprehensive range of cameras with USB 3.1, USB 3.0, USB 2.0, GigE interfaces and other innovative machine vision products are renowned for their high quality and ability to meet the performance requirements of demanding applications.

Automated Imaging Association ISO 9001:2015 certified

Contact us